Method of preventing sulphur dioxide in smelter gases



Jan. 15 1924.

G. C. CARSON METHOD OF PREVENTING SULPHUR DIOXIDE IN SMELTER GASES Filed may 21, 1917 IJNVENTOR.

WITNESS:

Patented Jan. 15, 1924.

PATENT "OFFICE.

GEORGE CAMPBELL CARS ON, OF SAN FRANCISCO, CALIFORNIA.

METHOD OF PREVENTING SULPHUR DIOXIDE IN SHELTER GASES;

Application filed May 21,

To all whom it may concem: Be it known that I, Gnonon CAMPBELL CARsoN, a citizen of the United-States of America, residing San Francisco, (jalifornia have invented a new and useful Method of Preventing Sulphur Dioxide in Smelter Gases, of which the following is a specification.

The object of my invention is to prevent at 89' Broadway Street,

1917. Serial No. 170,092.

ing of the oxygen or to reduce any SO that forms.

-. Blast furnace and roaster gasesare too cold to be treated by thismethod. Reverberatory furnace gases are generally sufficiently hot to dissociate the oxygen and sulphur of S0 Where side feeding and fetling furnacesare used,'the furnace gas is produced at a temperature of 2400 to 2700 degrees the production of sulphur-dioxide in metal- Fahrenheit and that portion of the furnace 'lurgical operations which I accomplish'in the following manner. Sulphur-dioxide, when heated to temperatures ranging above the smelting temperature of the usual sulphide materials treated in metallurgical roasting and smelting operations, dissociates intosulphur aiid'free oxygen. The temperatures which I prefer are around and above twenty-three hundred F. In practicing my nearest to the flue can be used for a fixing chamber to fix the oxygen and prevent its reunion with. the sulphur.

The medium utilized to spray the sulphides or whatever agent is used to fix the oxygen should be a gas whose oxygen is inert, such as chimney gases or producer gas, S0,,or the like; in order to prevent the introduction of active oxygen from the air invention I maintain a heated atmosphere into the fixingchamber.

heated to the oint and above the temperature of dlSSOClELtlOIl of sulphur dioxide and pass the sulphur bearing gas through this heated atmosphere which effects the dissociation of the sulphur and the oxygen of sulphur dioxide and while dissociated I fix the oxygen of the atmosphere by spraying into it an oxidizable material to prevent it recombining with the freed sulphur vapor upon cooling.

At temperatures above the smelting point of sulphide materials SO breaks into 20-l-S; and while dissociated I spray ore containing zinc sulphide after being'ground to a fine state of division into the heated gas. The finely powdered ore gives up its sulphur to enrich the sulp'hurcontent of the gas, and the zinc becomes an oxide or soluble sulphate by combining with. oxygen that would have combined wlth sulphur when the gas cooled suflicient to permit the combination. When zinc sulphide is not available, other sulphides can be"used. The reaction that takes place is: MS 4O ---l\/ISO or MS+2O=SO +M. The O dissociates as soon as formed, and sets free its oxygen to combine with M thus: 2M+20=2MO.

Coal dust, producer gas or other carbonaceous fuels can be substituted for metallic sulphide when desired. An amount of. coal dust or carbonaceous fuel should be injected into the gas before it cools to the point of formation of SO to insure the completefix- The invention is further described by ref-- erence to the accompanying drawings of which Fig. 1 is a cross-section and Fig. 2 a longitudinal section through a furnace adapted or altered to carry on the process,

Like reference numerals refer to like parts in both figures. In Fig. 1 the ore to be treated is fed so as to form a sloping embankment resting upon the floor and a'gainst the walls of the furnace chamber. This ore is sulphide material and is oxidized by forcing airthrough the tuyeres 1 upon the sides of the furnace chamber-and saturating the embankment with oxygen. When air is .used it impinges from the tuyere into the heated sulphide material and oxidizes the sulphur to S0 This SO passes from the embankment into the furnace chamber and as it does so it progresses into a temperature where it breaks into elemental sulphur temperature 1s fixed by spraying into it oxidizable materials such as sulp ide ores, coal dust, powdered peat, sawdust and like material or sulphide ores through pipes and oxygen and is mixed with the furnace he oxygen set'free from SO by high or vapor which-passes out the flue 5 to the precipitating or dust chamber.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A method of treating materials yieldingsulphur-dioxide upon oxidation and preventing the production of the sulphur-diox-.

ide consisting of treating said materials within a temperature where sulphur-dioxtio ide dissociates into sulphur and oxygen and fixing said oxygen while dissociated from said sulphur with an oxidizable material.

2. A method of treating sulphide ores con- I which consists of introducing them in a di'-' vided condition into a gas mixture produced by heating an oxide of sulphur to dissocia- GEORGE CAMPBELL CARSON.

v Witnesses:

S. E. BRETH RTON, From HALL. 

